Cardiology

Question 1

Right Ventricular Outflow Tract (RVOT) Tachycardia

Answer 1

• form of monomorphic VT that originates from the right ventricular outflow tract or occasionally tricuspid annulus
• characterised on ECG as VT with LBBB morphology and positive negative leads
• occurs either as idiopathic VT without any structural heart disease (most common) or rarely in ARVD
• idiopathic RVOT considered benign arrhythmia with no sig risk of SCD, triggered by sympathetic activation
• mx: 1. avoid triggers, 2. beta blocker/CCB 3. cardiac ablation

Question 2

Tetralogy of Fallot

Answer 2

• Involves: 1. VSD 2. Overriding aorta 3. RVOT obstruction 4. RVH
• surgery involves 1. repair of VSD 2. reconstruction of RVOT
• long term sequelae are: 1. pulm regurg (all - 71% severe) 2. RV dilation (all) 3. residual/recurrent rvot obstruction (40%) 4. VSD patch leakage (10%) 5. VT (5%)

Question 3

Eisenmanger Syndrome

Answer 3

Pathogenesis
1. Long-standing untreated left to right cardiac shunt (VSD/ASD, rarely PDA)
2. Progressive pulmonary hypertension and right ventricular hypertrophy
3. Pressure right heart exceeds left heart and shunt becomes right to left
4. Impaired oxygen delivery and cyanosis
5. Polycythemia with hyperviscosity, capillary damage and high thromboembolic risk
Pregnancy
-considered ‘contraindicated’
-maternal mortality around 50%, with also high foetal mortality/morbidity
-usually death from VTE/hypovolemia/preeclampsia/cerebral hypoperfusion leading to strokes
Treatment
-Lung transplant + cardiac transplant/repair of defect or conservative

Question 4

Arrhythmogenic right ventricular dysplasia

Answer 4

• autosomal dominant disease with incomplete penetrance characterised by fibrofatty infiltrate of the right ventricle due to mutations in desmosomes
• suggestive ECG: epsilon waves V1-V3, TWI V1-3, QRS >110ms V1-V3, RVOT
• clinical sequelae: RVOT, RV thrombus -> PE, RV dysfunction
• management: antiarrhythmic (sotalol best), anticoagulaton, can trial catheter ablation, ICD in most, transplant if refractory VT or severe biV failure, screening in 1st degree relatives

Question 5

Brugada syndrome

Answer 5

• autosomal dominant with incomplete penetrance, common cause of SCD, particularly in South East and South Asians
• dysfunctional sodium channel, most common mutation in SCN5A
• ECG patterns:
  - type I: coved ST segment elevation with J point >2mm in >1 of V1-V3 followed by a negative T wave
  - type II: saddle-back pattern ST elevation with J point >2mm and >1 mm ST elevation with a positive or biphasic T-wave in V1-3
  - type III: type I or II appearance but J point elevation <2mm and STE <1mm
• Clinical criteria:
  
  • documented VF or polymorphic VT
  • family history of sudden cardiac death at <45 years old
  • type I ECG in family members
  • syncope
  • nocturnal agonal respiration
  • inducible VT with programmed electrical stimulation
• Diagnosis of BS based on type I ECG + 1 clinical criteria
• If type II or III ECG try to observe type I ECG by: recording V1/2/3 all in 2nd L ICS, Holter monitor and observing nocturnal ECG, drug provocation test with fleicanide or ajmaline
• ICD for everyone who meets BS diagnostic criteria (if no symptoms with type I ECG, EP study ?inducible VT)

Question 6

Wellens’ syndrome

Answer 6

Diagnostic criteria:
-Deeply-inverted (type B) or biphasic (type A) T waves in V2-3 (may extend to V1-6)
-Isoelectric or minimally elevated ST segment (< 1mm)
-No precordial Q waves
-Preserved precordial R wave progression -Recent history of angina
-ECG pattern present in pain-free state
-Normal or slightly elevated serum cardiac markers
Indicates severe proximal LAD lesion - should have LHC
NB: type A evolves to type B (not clinically distinct)

Question 7

ECG findings of LVH

Answer 7

Many criteria. 
Simplest is Sokolow-Lyon Index: 
-S in V1 + R in V5 or 6 (whichever larger) = 35mm or more
AND
-R in AVR = 11mm or more

Question 8

ESC indications for CRT in pt with SR

Answer 8

Chronic HF with LVEF <35% and class II or worse symptoms despite OMT for at least 3 months and either:

1. LBBB and QRS >120ms
2. Not LBBB and QRS >150ms

Question 9

Clinical signs of severity in AS

Answer 9

a

Question 10

Echo features of severe AS

Answer 10

Valve area - <1cm2
Peak velocity - >4m/s
Mean gradient - >40mmHg
DI <25

Question 11

Absolute contraindications for stress testing

Answer 11

• AMI within 2 days
• Unstable angina
• Uncontrollled arrythmias with haemodynamic instability
• Symptomatic severe valvular stenosis
• Uncontrolled symptomatic heart failure
• Active endocarditis/myocarditis/pericarditis
• Acute aortic dissection
• Acute PE